let travel_ul=document.querySelector('.travel_ul');
let pic=document.querySelectorAll('.pic');

let index1=0;
let time1;

function Position1(){
    travel_ul.style.left=(index1 * -100)+'%'
}
function add1(){
    if(index1 >= pic.length-1){
        index1=0;
    }
    else{
        index1++;
    }
}
function desc1(){
    if(index1 < 1){
        index1= pic.length-1;
    }
    else{
        index1--;
    }
}
function timer1(){
    time1=setInterval(()=>{
        index1++;
        desc1();
        add1();
        Position1();
    },5000)
}
timer1();